Ornamental watch case

ABSTRACT

An ornamental watch case is disclosed having unique properties of hardness and brilliance, permitting its functional use and its use as an ornament of jewelry. At the same time, the watch case is made of a cobalt chromium alloy which readily lends itself to precision casting at greatly lesser expense than the technique presently used for watch manufacture.

United States Patent Pissarevsky [451 Jan. 18, 1972 [54] ORNAMENTALWATCH CASE [72] Inventor: Gregory J. Pissarevsky, 5535 Netherland Ave.,Riverdale, NY. 10471 [22] Filed: Mar. 14,1969

[21] Appl.No.: 807,398

[52] US. Cl ..75/171, 58/88 [51] Int. Cl. C224: 19/00 [58] Field ofSearch ..75/l7 l 170; 148/32, 32.5;

[56] References Cited UNITED STATES PATENTS 1,958,446 5/1934 Prange"75/171 Primary Examiner-Richard 0. Dean Attomey-Pennie, Edmonds,Morton, Taylor and Adams ABSTRACT 3 Claims, No Drawings less expensivewatches, by stamping the body of the case from steel, brass or nickel ortheir alloys. Such watch cases may be chrome-plated or gold-platedandrequire during their manufacture a multiplicity of steps which greatlyincrease the expense of the finished product. For example, a simplestamped case containing the bezel portion manufactured of stainlesssteel and including finishing machining steps will cost from $2 iii-$3in the United States at the present time. l-lot forging of stainlesssteel followed by finished machining is somewhat more expensive, yet thefinished product is inferior in many ways for the intended purpose. Theappearance of the case is dictated by its method of manufacture whichprovides largely a functional appearance. Whatever pleasing orornamental effect may be given to the case initially will be quicklydestroyed by wear, since stainless steel scratches very easily. I

In order for watch cases to be considered items of jewelry, it has beengenerally necessary to manufacture the case of solid gold, for example,or to gold-plate the case. Generally, gold cases are expensivelymachined, and, as in the case of stainless steel, are subject toscratching.

It is the object of the present invention to present a method andproduct of manufacture which will produce a watch case from a particularalloy which has superior characteristics of manufacture, brilliance,hardness and nontoxicity, obviating many of the difficulties ofmanufacture found in the prior art.

It is a further object of the invention to disclose a method and amaterial for the precision casting of watch cases which is a smallfraction of the cost of prior techniques, yet producing a watch case ofthe highest dimensional accuracy and quality.

It has been discovered that watch cases of various designs, bothfunctional and ornamental, may be constructed with extreme simplicityand precision, at greatly reduced expense by the use of an alloy havingsuperior properties for the purpose. The alloy, which contains majorpercentages of chromium and cobalt, is readily cast into the mostintricate and precise shapes, and has the property of not shrinkingduring casting while being entirely free of voids, bubbles and othercasting defects. Moreover, the alloy can achieve an extremely highlustre while its hardness assures permanency of appearance. The alloydoes not corrode and is completely nontoxic, having heretofore been usedprimarily for prosthetic applications, both internal and external, ofthe body. More particularly, the alloy used in carrying out theinvention has generally the following preferred composition: cobalt60-65 percent; chromium 25-30 percent; balance molybdenum with perhapssome traces of silicon and manganese.

The foregoing proportions are necessarily representative and somevariation of the respective percentages or ofthe constituent parts canbe permitted and still achieve the beneficial effects of the presentinvention. For example, cobalt and chromium percentages of about 50percent and 20 percent, respectively, can be tolerated together withabout 10 percent nickel, 15 percent tungsten and trace elements of iron(2.5 percent), carbon, silicone, manganese( l .5 percent), phosphorousand sulfur.

A precision cast watch case which includes the main body or bezelportion thereof may be made according to the teachings of the presentinvention in the United States for approximately 60-70 cents, includingfinal polishing. This is only a small fraction of the cost of producingwatch cases of other materials and by other manufacturing methodspresently known in the art. Various ornamental effects may readily becast without significant increase in cost. Yet the final product of theinventionis superior in durability, will not corrode, is nontoxic,nonmagnetic and takes a very high lustre.

I claim:

1. A watch case of cast metal, said metal being an alloy consistingessentially of: chromium 20-30 percent; Molybdenum 0-15 percent;tungsten 0-15 percent, nickel 0-l0 percent;

iron 0-2.5 percent; manganese 0-1.5 percent; balance cobalt, andincidental impurities such as carbon, silicon, phosphorous, and sulfur.

2. A watch case according to claim 1 wherein the composition of saidalloy is approximately 60-65 percent cobalt; 20-30 percent chromium;balance molybdenum, manganese, and silicon.

3. A watch case according to claim 1 wherein the composition of saidalloy is approximately 50 percent cobalt, 20 percent chromium, 15percent tungsten, 10 percent nickel, balance of iron and manganese withimpurities of carbon, silicon, phosphorous, and sulfur.

2. A watch case according to claim 1 wherein the composition of saidalloy is approximately 60-65 percent cobalt; 20-30 percent chromium;balance molybdenum, manganese, and silicon.
 3. A watch case according toclaim 1 wherein the composition of said alloy is approximately 50percent cobalt, 20 percent chromium, 15 percent tungsten, 10 percentnickel, balance of iron and manganese with impurities of carbon,silicon, phosphorous, and sulfur.